'72 240Z Rebuild

[siteunseen]

1 minute ago, Redwing said:

Deanna just sits there waiting for me to come back!  

I knew you had a female. 8^(

All dogs are boys to me. "Here boy!" Can't help it.

Cats are kittens too, no matter how old. " come here kitty kitty"

[Zed Head]

4 hours ago, siteunseen said:

Well fooey!

Everything worked and it cranked right up. Went to set fast idle at 2,000 rpm by my timing light. got in to watch the temp gauge. Nothing. None of my gauges worked. Pulled the fuse box cover and the IGN 20 amp as smoked. Shut it down. 

I put a new alternator on and that's all I changed electrically. I will get some new glass fuses and unhook the new alternator to see if my gauges come to life, tomorrow. I'm beat!

Carbs got super warm too. I will close off that coolant circuit too and see what happens. I've got something wrong somewhere in the coolant routing. 

Sounded great for about five minutes!

I was wondering if you were going to crank it up.  I would test for shorts with a meter or test probe first.  Check from the power supply side to ground of things that only get power when the key is On.  Something will show continuity to ground that shouldn't.  The charge wire, white-red, from the alternator is hot as soon as you connect the battery, so not IGN controlled.

[siteunseen]

Maybe I'll find something associated with you he a/c. I pulled out all of that too.  Thank you Zed Head, I'll find it sooner or later. Most likely later. 8^)

[Zed Head]

That's a possibility.  

Check out the "Help Identify this part..." thread.  Horn buttons, early and late.  You have all of them.  I suggested you as a source of knowledge.

[siteunseen]

I got a call today about a lime yellow 240 a guy needs to get rid of. Hopefully I can see it soon. I love that color and its original, no paint job. Needs struts and brakes. Perfect to me!

I'll let you know with pictures.

Thanks again.

[siteunseen]

On 4/26/2016 at 4:21 PM, siteunseen said:

Well fooey!

Everything worked and it cranked right up. Went to set fast idle at 2,000 rpm by my timing light. got in to watch the temp gauge. Nothing. None of my gauges worked. Pulled the fuse box cover and the IGN 20 amp as smoked. Shut it down. 

I put a new alternator on and that's all I changed electrically. I will get some new glass fuses and unhook the new alternator to see if my gauges come to life, tomorrow. I'm beat!

Carbs got super warm too. I will close off that coolant circuit too and see what happens. I've got something wrong somewhere in the coolant routing. 

Sounded great for about five minutes!

Well I got lucky for a change!  After reading about Dave Irwin's plug for the ZX alternator upgrade I found what I'd done.  Dipstick of the day award for me.   I put an alternator for my '77 280 on my 240, as Steve J said "that's bad mojo".  240s have external regulators, 280s have internal.  DON'T DO THIS

Ignition feedback burnt the fuse and killed my gauges.  " The ZXP does all the required connecting in a clean, simple plug. The ZXP introduces a Jumper and a Diode that must be installed to prevent ignition feedback, which will power the ignition with the key in the off position."

I unhooked the new alternator and replaced the IGN fuse and my gauges twitched when I turned the key, fuel gauge came up and the voltage gauge moved.  

Now I'm plugging all the coolant lines that go to the carbs.  Fingers crossed and salt thrown over my back, looking for a rabbit too_ I'm gonna put him in a wheelchair. 

I may start it again in the morning and try to get through the 20 minute run in.  So far I've only gotten to 5. 

 

[Zed Head]

Aack.  The 77 used external.  I think that you mean that you should have used a ZX alternator with Dave's ZXP plug.  The 77 alt is essentially the same as a 240Z alt.  78 and up is what you want with the plug.

[siteunseen]

Here's the new one I took off and the old one I'm putting back on for now. Then I'm buying all Dave's stuff to modernize this old car.

[Zed Head]

Those are both external.  The F and the N of the "T" plug tell the story.  Internal uses S and L.  I'm using an ancient 1981 280ZX wrecking yard alternator on my converted system.  My parts sore alt crapped out and never had much juice at low RPM.

[siteunseen]

So if put the old one it's gonna blow the ignition fuse again?

[Zed Head]

Actually, it doesn't seem like that would be the cause of your problem, but I don't know for sure.  The L wire would be running to F or N which might be a  short and pull enough through the Lamp to blow the fuse.  The S wire might be doing the same but that should happen as soon as it's plugged in.

CO, SteveJ, or Dave might know the circuit well enough to say.  240Z circuits are bit odd.  Either way, you'll need a ZX alternator to use with Dave's ZXP plug.  You could just get the right one and try it.  Worst case you waste another fuse.

[S30Driver]

Possibly the newer one has a serious problem.  Is it a rebuilt from a parts store?